Document containing security images

ABSTRACT

A document containing security images which enable original documents to be distinguished from copies of the originals. The document  60  bears an image  63  containing a latent image  68 . Latent image  68  may be formed from two or more images  65  and  66 . The first image  65  is preferably formed at a high line frequency and at a first angle in one or more colors. The second image  66  is preferably formed at a lower line frequency at the same angle as first image  65  and in one or more colors. The colors in the first image  65  and the second image  66  are preferably chosen so that latent image  68  has substantially the same color as image  63.

This application is the U.S. National Phase under 35 U.S.C. §371 ofInternational Application No. PCT/JP2004/014517, filed May 10, 2004,which in turn claims the benefit of U.S. application Ser. No.60/473,951, filed May 29, 2003, the disclosures of which Applicationsare incorporated by reference herein in their entirety.

This application is a continuation in part of PCT ApplicationUS2004/001360 which claims the benefit of U.S. Provisional ApplicationNo. 60/443,288 filed Jan. 29, 2003, U.S. Provisional Application No.60/443,289 filed Jan. 29, 2003, and U.S. Provisional Application(unknown) filed January (unknown), and also is a continuation in part ofPCT Application US03/32159 filed on Oct. 9, 2003 which claims thebenefit of each of the following U.S. provisional applications filedOct. 10, 2002; 60/417,750; 60/417,751; 60/417,752; 60/417,753;60/417,754; 60/417,755; 60/417,756; 60/417,757; 60/417,758. Thisapplication claims the benefit of U.S. Provisional Application No.60/473,951 filed May 29, 2003 titled PRISMATIC HOLOGRAPH. Each of theabove applications are herein incorporated by reference in theirentirety.

FIELD OF THE INVENTION

This invention relates generally to document protection methods andproducts, and more particularly to methods and products for printing andobtaining original documents that can be readily differentiated fromcopies made of those documents. The document protection methods andproducts also allow detection of an original document by a documentreader.

BACKGROUND OF THE INVENTION

Many methods and products have been developed, for example, to detercounterfeiting of valuable documents including art work, identificationdocuments or financial instruments such as currency, so thatunauthorized copies attempted to be made from those documents can bereadily distinguished from the originals. Most of these methods andproducts involve preparing an original document by printing orlithography on high quality media such as silk, rice paper, and highcontact rag paper. The printing of original documents may be done eitherin black-and-white (B&W) or in color, and if in color, either in spotcolor, colored backgrounds and/or multicolor printing. In the case ofcolor, the tendency has been in the direction of using multiple colorsfor original documents for aesthetic value, for ease of recognition, andoriginally for protection from copying by conventional means. The commonprinting processes of valuable originals, whether in B&W or in color,are intaglio and gravure, among others. These and the other processesmentioned in this application are very well known in the art and willnot be discussed in great detail.

Most of the useful examples in the prior art to deter counterfeiting andthe like are intended to ensure that copies are produced either with aclear moiré pattern or with a “latent image” indicia which is invisibleor nearly invisible to the naked eye on the original document. The term“latent image” is used here not in the photographic sense of an unseenimage to be developed after processing by chemical reaction, but toindicate indicia that are printed on originals so as to be nearlyinvisible to the naked eye.

These and other developments in the prior art for purposes of providingdocument protection are disclosed in the patent literature, as forexample, in U.S. Pat. No. 5,018,767 issued May 28, 1991; U.S. Pat. No.5,193,853 issued Mar. 16, 1993; and U.S. Pat. No. 3,675,948 issued Jul.11, 1972; and U.S. Pat. No. 4,143,967 issued Mar. 13, 1979, all to RalphC. Wicker; in U.S. Pat. No. 4,227,720 issued Oct. 14, 1980 and U.S. Pat.No. 4,310,180 issued Jan. 12, 1982 both to William H. Mowry, et al, aswell as U.S. Pat. No. 5,149,140 issued Sep. 22, 1992 to Mowry et al; andin U.S. Pat. No. 5,487,567 issued Jan. 30, 1996 to John R. Volpe. All ofthese patents disclose various means for providing methods and productsto enable copies of documents to be distinguished from the originals, asfor example, by a “large dot-small dot pattern”, a “close line-spacedpattern”, and images or indicia which are screen printed at minutelyvaried spaces and/or angles on the originals and are intended to producea highly visible moiré pattern effect on the unauthorized copies. Inthis specification, the words “print”, “printed” and “printing” are usedto refer to the making of an original document regardless of thetechniques used, and the words “copy” and “copying” to refer to makingcopies from an original.

It is well known, however, that copier and computer scanner-printertechnology has become even more sophisticated since the development ofthe prior art in document protection. The goal of copier technology, ifnot already achieved, has been, especially in desktop publishing and thelike, to obtain copies as good as an original. “What you see is what youget” in color documents has become very achievable in copier andduplicator equipment including scanning input devices. Even desk-topcomputers have become sufficiently sophisticated in color reproduction,including color matching of copies to color standards such as thePANTONE.RTM. Color Matching System.

Many if not all of the document protection methods and products weredeveloped before this very significant improvement in copier andcomputer reproduction technology, and have been found not be aseffective in the newer color reproduction technology. This is especiallythe case on color copiers with a “photo” setting that intentionallycopies a document in an “unsharp” focus so as to give the effect of acontinuous tone image, the effect of which is to defeat the precise linevariation between the copier scanner and the security pattern on thedocument original. These prior art techniques for document protectionmay not work as reliably against the many forms of copier/duplicator andcomputer scanner/output equipment now or soon to be available.

Thus it has become imperative for purposes of document security andsafety that further improvements in the area of document protection befound, especially where there is a need to prevent copying orduplicating of valuable originals and readily distinguishing the copiesfrom the originals.

SUMMARY OF THE INVENTION

It is an object of the invention to overcome the above problems andprovide enhanced security for documents.

A document carrying an image may comprise a background portion printedat a first line frequency and at a first color; a first image portionprinted at a second line frequency and a second color; and a secondimage portion printed at the second line frequency and a third color,wherein a combined image the first image portion and the second imageportion appear to be substantially the same color as the first color. Inthe document, the first image portion may include printed lines, dots orspots, and the second image portion may include printed lines dots orspots placed between adjacent printed lines dot or spots of the firstimage portion. In the document, the first image portion may be printedat a density between 5 percent and 95 percent of the combined image ofthe first and second image portions. When the document is reproduced bya copying or scanning device, a solid tonal color may be reproduced inthe area of the first image portion and the second image portion insubstantially the same color at the first color, thereby not reproducingthe first image portion and the second image portion.

A document carrying an image may comprise: a background portion havingprinted lines dots or spots at a first angle and at a first color; animage portion having printed lines dots or spots at substantially thesame color as the first color and at a different angle than the firstangle, wherein when the document is reproduced by a copying or scanningdevice, a solid tonal color may be reproduced in the area of the imageportion in substantially the same color at the first color, thereby notreproducing the first image portion. In the document, at least one ofthe background portion and the image portion may be printed at a linefrequency greater than about 175 lines per inch.

A document carrying an image may comprise: a background portion havingprinted lines dots or spots at a first angle and at a first linefrequency; an image portion have printed lines dots or spots at a secondangle and at a second line frequency, wherein the first line frequencyis at least two times greater than the second line frequency. In thedocument, the first line frequency may be greater than about 175 linesper inch. In the document, an image formed by the image portion may besubstantially hidden, and when the document is reproduced by a copyingor scanning device, the image formed by the image portion is notsubstantially hidden in the reproduced document.

A document carrying a latent image may comprise: a first image portionformed at a first color; a first latent image portion printed at a firstline frequency at a first angle and a second color; and a second latentimage portion printed at the second line frequency lower than the firstline frequency at substantially the first angle and a third color,wherein a combined image the first latent image portion and the secondlatent image portion may form substantially the same color as the firstcolor. In the document the first latent image portion may includeprinted lines, dots or spots, and the second latent image portion mayinclude printed lines dots or spots placed between adjacent printedlines dot or spots of the first image portion. When the document isreproduced by a copying or scanning device, a composite image of thefirst latent image portion and the second latent image portion may beformed as a visible image in a copy of the document. In the document,the first image portion may be a holographic image. In the document, thefirst image portion may be art work, and the first latent image portionand the second latent image portions may be formed after the creation ofthe art work or at the same time as the art work. In the document, thefirst image portion may be a photograph, and the first latent imageportion and the second latent image portions may be formed after thecreation of the photograph or at the same time as the photograph. A copyof the document may contain distortions.

An apparatus for authenticating a document as an original document maycomprise: a magnification unit capable of magnifying images contained onthe document; a scanning unit capable of scanning images magnified bythe magnification unit and creating an electronic format of the imagescontained on the document; a microprocessor which receives theelectronic format and determines if the document contains predeterminedsecurity images which are not reproduced when the a reproduction of thedocument is made by a copying or scanning device. In the apparatus, themicroprocessor may compare a layout of the document to a layout of theoriginal document, and the microprocessor may determine the document tobe an original document if the layout of the document corresponds to thelayout of an original document. The apparatus may further comprise adisplay which displays a message indicative of whether the document hasbeen determined to be an original document.

A method of authenticating a document as an original document maycomprise the steps of: reviewing the document for the presence ofpredetermined security images which are not reproduced when areproduction of the document is made by a copying or scanning device;and determining the document not to be an original if the predeterminedsecurity images are not present in the document. The method may furthercomprise the steps of comparing a layout of the document to a layout ofthe original document, and determining the document to be an originaldocument if the layout of the document corresponds to the layout of anoriginal document. The method may further comprise the step ofdisplaying a message indicative of whether the document has beendetermined to be an original document.

A computer readable medium may carry instructions to cause a computer toperform a method of authenticating a document as an original documentcomprising the steps of: reviewing the document for the presence ofpredetermined security images which are not reproduced when areproduction of the document is made by a copying or scanning device;and determining the document not to be an original if the predeterminedsecurity images are not present in the document. In the computerreadable medium, the method may further comprise the steps of comparinga layout of the document to a layout of the original document, anddetermining the document to be an original document if the layout of thedocument corresponds to the layout of an original document. In thecomputer readable medium, the method may further comprise the step ofdisplaying a message indicative of whether the document has beendetermined to be an original document.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part ofthe specification, together with the description serve to explain theprinciples of the invention. In the drawings:

FIG. 1 illustrates a document having a latent security image;

FIG. 2 illustrates another embodiment of a document having a latentsecurity image which is hidden to the human eye;

FIG. 3 illustrates another embodiment of a document with a latent image;

FIG. 4 illustrates a document which contains a dedicated security image;

FIG. 5 illustrates a document which contains a latent image in the formof a bar code;

FIG. 6 illustrates a document which contains an image which containsdistortion or moiré inducing patterns;

FIGS. 7A and 7B illustrate an exemplary safety medium which prohibitsreproduction of the information contained on the medium;

FIG. 8 illustrates a document having a latent security image;

FIGS. 9A and 9B illustrate documents containing a plurality of securityimages;

FIG. 10 illustrates an exemplary reading device for detecting securityimages in a document;

FIG. 11 illustrates an exemplary method of authenticating a document tobe an original using the exemplary reading device of FIG. 10;

FIG. 12 illustrates an exemplary bar code reader capable of detecting abar code as a latent image;

FIG. 13 illustrates a document which contains an exemplary conductiveimage;

FIG. 14 illustrates a an exemplary verification device for verifying adocument with a conductive image.

FIG. 15 illustrates an exemplary apparatus for detecting illegalpublishing of documents; and

FIG. 16 illustrate an exemplary method for detecting illegal publishingof documents.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a document 1 having a latent security image 2 whichis generally hidden to the human eye. In FIG. 1, a background area 3 ispreferably printed at a high line frequency. An image 2 is printed witha first color 4 at a predetermined density and printed with a secondcolor 5 also at a predetermined density. The result is that image 2appears as a third color to the human eye. Preferably, background area 3is printed in the third color or a color similar to the third color,causing image 2 to be obscure to the eye.

The image 2 may be formed by printing the first color 4, such as byprinting lines 6 having a first color at predetermined pitch andthickness. Then the second color 5 may be printed such as by printinglines 7 having a second color between lines 5 at a predetermined pitchand thickness, such as by using a negative image of image 2. Those ofskill in the art will appreciate that lines 6 and 7 may be printed in asingle print operation as well, such as by using a laser printer or thelike. Also, although only two colors are discussed for purposes ofillustration, those of skill in the art will appreciate that more thantwo colors may be used, including six or more colors.

Preferably, the density of lines 6 and 7 are controlled by controllingthe pitch (distance between lines), thickness of the lines 6 and 7, orby controlling the density of the medium, such as ink, used to printlines 6 and 7. The density of lines 6 and 7 may range from 5% to 95%depending on the colors selected for lines 6 and 7, the density of themedium, the thickness of the lines, and the desired appearance of image2. In an exemplary embodiment, a density of 50% for each of lines 6 and7 may be used, with a red color for line 6 and a green color for line 7.Also in an exemplary embodiment, lines 6 and 7 may be printed at adifferent angle than used to print background 3.

Image 2 may be detected using a reading device which magnifies the imageto reveal the two colors, or selectively screens one of the two colors.Latent image 2 preferably may also be detected using an appropriatelyconfigured magnification device, such as a document verifying device asdescribed in U.S. Pat. No. 5,735,547, herein incorporated by reference.When document 1 is copied or scanned by conventional copying or scanningdevices, such as a color photocopier, image 2 is substantially notreproduced in the copy. Particularly, the copy of document 1, even if inthe same color tone as the original document 1, will contain backgroundarea 3 across the entire document, and will not contain image 2. Thepresence or absence of image 2 may be used to determine if a document isan original or a copy, respectively.

FIG. 2 illustrates a document 10 having a latent security image 14 whichappears hidden to the human eye. As illustrated in FIG. 2, document 10preferably has a background area 11 which contains lines 12 of a highfrequency, such as about 175 lines per inch or more. Lines 12 preferablyhave a color. Image 14 preferably contains lines at about the samefrequency but at a different angle from lines 12. Lines 12 and or 15 maybe lines, dots or spots.

In an exemplary implementation of the concepts of FIG. 2, lines 12 maybe printed in blue at an angle of 30 degrees with a frequency of 280lines per inch, and lines 14 may be printed at 45 degrees in blue andalso with a frequency of 280 lines per inch.

Image 14 may be detected using a reading device which magnifies theimage to reveal lines 15 or selectively screens lines 12 to reveal lines15. When document 10 is copied or scanned by conventional copying orscanning devices, such as a color photocopier, image 14 is substantiallynot reproduced in the copy. Particularly, the copy of document 10, evenif in the same color tone as the original document 10, will containbackground area 11 across the entire document, and will not containimage 14. The presence or absence of image 14 may be used to determineif a document is an original or a copy, respectively.

FIG. 3 illustrates a document 20 with a latent image 22. Document 20contains a background area 21 which is preferably printed at a firstfrequency, such as 175 lines per inch or greater, and at a predeterminedangle. Image 22 is preferably printed at lower frequency than thefrequency of background area 21. Preferably, the frequency of lines 24in area 21 is greater than two times the screen frequency of lines 23 inimage 22. More preferably, the line frequency in area 21 is at leastthree times greater than the line frequency of lines 23 in image 22. Theangle of the lines 22 is preferably at a different angle than the angleof lines 24 by at least 5 degrees. The width of lines 24 and 23 may beselected to provide a continuous aesthetically pleasing appearance ofthe document. Both lines 24 and 23 preferably have the same color.

In an exemplary implementation of a security document using theprinciples illustrated in FIG. 3, lines 24 in background area 21 mayhave a frequency of at least 175 lines per inch and preferably of 300lines per inch, and a line width of 0.0025 inches at a 45 degree angle,and lines 23 in image 14 may have a frequency between 100-133 lines perinch and preferably a frequency of 95 lines per inch at a 30 degreeangle.

FIG. 4 illustrates a document 30 which contains a dedicated securityimage 33 having a plurality of high and low frequency portions. Asillustrated in FIG. 4, document 30 preferably has a background area 31.Image 33 preferably contains first segments 34 which contains lines 35which range from a high frequency to a low frequency and second segments36 which contain lines 37 which range from a low frequency to a highfrequency. Although two segments are shown for each of the first andsecond segments 34 and 36, respectively, any number of segments may beused, including one segment for either segment 34 and 36. The linefrequency in each of segments 34 and 36 may change continuously in alinear or non-linear manner or stepwise from one terminal end of each ofsegments 34 and 36 to the opposite terminal end, respectively. Each oflines 35 and 37 may be printed in black or in any color.

If image 33 is reproduced by conventional copying or scanning devices,the reproduced image will preferably show significant distortions, suchas moiré patterns.

FIG. 5 illustrates a document 40 which contains a latent image 43 in theform of a bar code. As illustrated in FIG. 5, document 40 contains abackground area 41 which contains lines 42 at a predetermined frequencyand predetermined angle. Image 43 preferably contains a plurality ofbars 44 which may form a bar code which may contain information readableby a bar code reader. Bars 44 preferably contain lines 45 at apredetermined frequency, which may be the same frequency as lines 42.Lines 45 may preferably be printed at a different angle than lines 42 asdiscussed in the construction of FIG. 3, or lines 45 and 42 may beprinted in similar colors as discussed in the construction of FIG. 2 andFIG. 1. Any suitable technique for providing a latent bar code imagethat may not be reproduced may be used. In an exemplary construction inaccordance with the concepts of FIG. 5, lines 42 and 45 may each beprinted at the same frequency, which is a frequency between 150 to 400lines per inch.

Image 43 may be detected using a reading device which magnifies theimage to reveal lines 45 or selectively screens lines 42 to reveal lines45. A bar code reader may then detect the bar code and read informationfrom the bar code. The information provided by the bar code may includedocument identifying information or other security information.

When document 40 is copied or scanned by conventional copying orscanning devices, such as a color photocopier, image 43 is substantiallynot reproduced in the copy. Particularly, the copy of document 40, evenif in the same color tone as the original document 40, will containbackground area 41 across the entire document, and will not containimage 43. The presence or absence of image 43 may be used to determineif a document is an original or a copy, respectively.

FIG. 6 illustrates a document 50 which contains an image 52 whichcontains distortion or moiré inducing patterns. As illustrated in FIG.6, document 50 contains a background portion 51. Image 52 preferablycontains a background portion 53 containing lines 57 at a predeterminedfrequency and multiple portions 54, 55 and 56 which have various linefrequencies which may be higher than or lower than the predeterminedfrequency of lines 57. For example, the line frequencies in portions 54,55 and 56 may be printed in one or more high frequencies, such asgreater than about 175 lines per inch while, background portion 53 maybe printed at a low frequency, such as about 100-135 lines per inch.Alternatively, the multi-frequency portions may range from a highfrequency in an area to a low frequency in an area next to a highfrequency area.

FIGS. 7A and 7B illustrate an image printed on a medium thatsubstantially stops reproduction of information contained on the medium.As illustrated in FIG. 7A, medium 701, such as paper, contains printedimages 702 and 703 that preferably interfere with scanners, facsimilemachines and laser copiers. A first set of printed images, representedby printed image 702 may be printed in a dark color such as black innegative form. Then a second set of printed images, represented byprinted image 703 preferably is a contact positive of the first printedimage 702 and may be printed in reflective ink, such as silver ink.Alternatively, as illustrated in FIG. 7B, one of the colors may beprinted over all of medium 705 as a solid image 706. Then the secondcolor in a negative form or a positive form image, depending on the formof the first image, respectively, may be printed on top of image 706. Inboth FIGS. 7A and 7B, reproduction of medium 702 and 705, respectively,will result in a black copy, making the information on medium 702 and705, respectively, unreadable.

FIG. 8 illustrates a document 60 which bears an image 63 containing alatent image 68. Image 63 may be formed of one more colors and latentimage 68 may be formed on document 63, each may be formed by being beprinted, embossed, dembossed, foil hot stamped, perfing, holographicprocesses or any other way to transfer an image to a media. Document 60may be a newly formed document or may be an existing art work orphotograph. Accordingly, latent image 68 may be added to existing artwork and photographs.

Latent image 68 may be formed from two or more images 65 and 66, each ofwhich may be formed of lines, dots, swirls, spots, real art work ortype. The first image 65 is preferably formed at a high line frequency,such as greater than about 175 lines per inch, and at a first angle inone or more colors. The second image 66 is preferably formed at a lowline frequency, such as about 50-135 lines per inch, at the same angleas first image 65 and in one or more colors. The second image 66 ispreferably formed between the lines, dot, swirls, or spots of the firstimage 65 and may be printed either in register or out of register. Thecolors in the first image 65 and the second image 66 are preferablychosen so that latent image 68 has substantially the same color as image63. If the document 60 is reproduced, the reproduced copy is preferablyvery distorted, such as containing moiré patterns, and the compositeimage of the first image 65 and the second image 66 preferably appearsin the reproduced copy. Accordingly, the latent image 68 protects anoriginal document from copying, for example, by using the visiblepresence or absence of latent image 68, an original document can bereadily discriminated from a copy.

As described in connection with FIGS. 10-11, the latent image 68 may bedetected in an original document by an appropriately configured readingdevice. Latent image 68 preferably may also be detected using anappropriately configured magnification device, such as a documentverifying device as described in U.S. Pat. No. 5,735,547.

Those of skill in the art will appreciate that any number of thesecurity images described in FIGS. 1-8 may be presented separately or incombination on a single document. FIG. 9A illustrates a document 100containing a plurality of security images 1, 10, 20, 30, 40, and 52,which are discussed in connection with FIGS. 1-7B. FIG. 9B illustratesan identification card 200 containing a plurality of security images 1,10, 20, 30, 40, and 52, which are discussed in connection with FIGS.1-7B. Although not illustrated, document 60 may also be included ondocument 100 and/or identification card 200.

Art work may be protected by applying a security image to a part of thework to enable an original work to be distinguished from a copy.

FIG. 10 illustrate an exemplary construction of a reading device whichmay be used to detect security images in document 100 or card 200. Asillustrated in FIG. 10, document 1001 containing security image 1007 maybe magnified by magnifying unit 1002 which provides a magnified image toscanning unit 1003. Security image 1007 may formed in accordance withone or more of the techniques illustrated in FIGS. 1-8. Magnifying unit1002 may be any conventional magnification device as known to those ofskill in the art and may be integrally formed with scanning unit 1003 ormay be independent of scanning unit 1003. Magnification unit 1002 mayenable an optical and/or a digitally enhanced magnification as known tothose of skill in the art. A preferred magnification device is capableof providing a magnification of less than 100% of the document image upto 1000% of the document image.

The scanning unit 1003 may be any conventional type of scanning unit,including scanning units capable of providing a digital image of aphotograph or of providing an electronic word processor document from atext scan. Scanning unit 1003 may be of the type suitable for use withphotographic and text scanners, photocopiers, facsimiles. Scanning unit1003 preferably generates a scanned representation of a scan of document1001 and security image 1007, such as a digital representation, andprovides this information to a microprocessor 1004. Scanning unit 1003may contain one or more storage devices (not shown), such as a RAM,floppy disk drive, writeable CD drive, or the like, which may be used tostore the scanned representation prior to being sent to themicroprocessor.

Microprocessor 1004 processes the scanned representation of document1001 and particularly of security image 1007. Preferably, microprocessorcontains verification software that compares the scanned representationof the document against a representation of the original documentpreviously stored in a memory associated with microprocessor 1004.Alternatively, microprocessor 1004 may retrieve the representation ofthe original document from a remote location, such as through a websiteor a secure communication link. Microprocessor 1005 may provide resultsof the comparison to a display 1005.

Microprocessor 1004 may also instruct an access device to provide accessto a user when a valid document or ID card is detected. Those of skillin the art will appreciate that an access device may include access to aroom or building through a security door and access to informationcontained on a data base through a secure access port or a firewall, ormay simply include access to complete a financial transaction.Preferably, access is denied when microprocessor 1004 determines thatscanned document 1004 is not an original document.

FIG. 11 illustrates an exemplary method of detecting valid originaldocuments using the reading device depicted in FIG. 10. As illustratedin FIG. 11, the scanned representation of document 1001 and arepresentation of a corresponding original document are retrieved by themicroprocessor in step S1. As illustrated in step S2, the microprocessor1004 reviews the scanned representation of document 1001 to determine ifpredetermined security images are present in the scanned document, thepredetermined security images are preferably images which are latentsecurity images which are not expected to be reproduced in a copy of thedocument, such as images constructed in accordance with the principlesof FIG. 3. If the predetermined security images are not present indocument 1001, NO in step S2, then microprocessor 1004 determines thatscanned document 1001 is not an original document, and may instructdisplay 1005 to display “COPY”, or “INVALID” or the like instructions.

If the predetermined security images are present in document 1001,microprocessor 1004 may indicate that the document is an originaldocument, or as an increased security measure, microprocessor 1004 mayanalyze the layout of the scanned document 1001, as illustrated in stepS3. The analysis of the layout may include analysis of the location ofprinted images, both visible images and latent images, analysis of thecolor, including black and white areas, and/or analysis of thefrequency, pitch and/or angles of lines of an image. The layout ofscanned document 1001 is compared to the expected layout of an originaldocument, as illustrated in step S4. If the layout of scanned document1001 does not match the expected layout of an original, NO in step S4,then the microprocessor 1004 determines that scanned document 1001 isnot an original document, and may instruct display 1005 to display“COPY” or “INVALID” or the like instructions. If the layout does matchthe expected layout, YES in step S4, microprocessor 1004 determines thatscanned document 1001 is an original or valid document and may instructdisplay 1005 to display “ORIGINAL” or “VALID”, or the like instructions.

FIG. 12 illustrates an exemplary device for reading a bar code imageformed on a document. As illustrated in FIG. 12, document 2001preferably contains a bar code image 2007 which is hidden to the humaneye. Magnifying unit 1002 preferably magnifies bar code image 2007 andprovides the magnified image to bar code reader 2003. Bar code reader2003 is preferably a conventional bar code reader capable of reading aplurality of substantially parallel lines and detecting at least one ofthe pitch, frequency and thickness of the plurality of the substantiallyparallel lines. Bar code reader 2003 provides the detected informationto a microprocessor 2004, which uses the detected information todetermine the content of recorded information in the bar code image2007. The recorded information may preferably include information of theauthenticity and identity of document 2007, such as the name of a personusing an identification card as document 2001.

Microprocessor may authenticate document 2001 carrying bar code 2007 inthe same manner as illustrated in FIG. 11, in which case bar code 2007,and the corresponding information recorded by bar code 2007, wouldpreferably be one of the detected security images in step S2. Forexample, as an increased security measure, bar code 2007 may be usedwith other security images and with the layout of document 2007 todetermine if document 2007 is an original or valid document. In thismanner, a counterfeit document or a copied document in which bar code2007 may have been successfully reproduced would result in the denial ofaccess.

The architecture illustrated in each of FIGS. 10 and 12, may be entirelycontained in a single device or multiple devices, and the functionsassociated with the architecture in FIGS. 10 and 12 may be performed byprogrammable software. Moreover, the operations illustrated in FIG. 11may be performed by programmable software on an internal or externalmemory (not shown) associated with microprocessor 1004 or 2004,respectively, such as a ROM or a RAM or any other memory. The softwarethat performs the operations illustrated in FIG. 11 may be embodied inthe form of data in a computer readable medium. A computer readablemedium within the scope of this disclosure includes any medium, physicalor metaphysical, which is capable of carrying information in a formwhich can be read by an appropriately configured computer or mobilecommunication device and associated peripheral devices of the computeror station, including, but not limited to: an optical readable/writeabledisc, a magnetic disk, a readable/writeable card, a magnetic tape, anelectrical transmission signal for wireline or wireless transmission oroptical transmission of data using electrical and/or electromagneticsignals. The data associated with the programmable software may be inthe form of packetized digital data.

FIG. 13 illustrates an exemplary conductive image 1200 on document 100,also containing a plurality of security images 1, 10, 20, 30, 40, and52, which are discussed in connection with FIGS. 1-8. Exemplaryconductive image 1200 preferably contains at least two contact areas1201 which are connected by a conductive trace 1202. In a preferredconstruction, contact areas 1201 and conductive trace 1202 may be hiddenor obscured from view by being elements of an image and/or beingimbedded. The conductive image 1200 may be used to verify the validityof the document. Those of skill in the art will appreciate that contactareas 1201 and conductive trace 1202 may be made of any suitableconductive medium, such as metallic pads or strips, conductive ink, orsuitable conductive materials.

FIG. 14 illustrates an exemplary reading device 1300 which may be usedto with conductive image 1200 to verify the document. The reading devicemay preferably be in the shape of a pen. Exemplary reading device 1300preferably contains a controller 1301 which provides a voltage acrosswires 1303 to cause a current to flow through probes 1304 when they areapplied to a valid document 100 having a conductive trace 1200. Whenprobes are placed on contact areas 1201, one probe on each area, thecurrent provided preferably flows through one of probes 1304, one ofcontact areas 1201, conductive trace 1202 to the other probe through theother contact area and back to controller 1301 through wire 1303, i.e.completing an electrical circuit. An indicator light 1302 is preferablyprovided which lights up when the current is passed through theconductive trace 1202 from one probe 1304 to the other, denoting a validdocument. Those of skill in the art will appreciate that indicator light1302 may consist of one or more single color LEDs, or LEDs of multiplecolors, which light up when a sufficient amount of current or voltage isreceived. For example, when an activation switch (not shown) is pressedon reading device 1300, indicator light 1302 may light up green if thecircuit has been completed (a valid document is detected), or may lightup red, or not at all, if the circuit has not been completed (thedocument is not valid).

Those of skill in the art will also appreciate that indicator light 1302may be replaced with an indicator display, such as a conventionalvoltmeter, which may display various attributes based on the receivedcurrent, such as the amplitude of the current or voltage or the measuredresistance of the conductive trace, and any of these values may be usedto determine if a document is valid.

FIGS. 15 and 16 illustrate an exemplary embodiment for detecting andinhibiting illegal desk top publishing of documents. As illustrated inFIG. 15 a document 1401 being scanned by scanning unit 1403 may containa security image 1407. Security image may preferably be an image made inaccordance with the principles discussed in connection with FIGS. 1-8 ofthis application. Microprocessor 1404 preferably contains a list ofprohibited images in memory 1412, such as U.S. currency (e.g. a U.S.$100 bill), and preferably stores a plurality of attributes of theprohibited images, such as at least one of a predetermined hidden ornon-hidden security image, the layout of the prohibited image orselected portions of the prohibited image, hidden or non-hidden artworkor bar codes on the prohibited image, the line characteristics such asline density, line style (e.g. lines, dots, spots) line patterns, andline color of a predetermined part or all of the prohibited image.

Microprocessor may receive images through the Internet from a web basedserver 1420 or from any other internal or external source, such as ahard drive, a CD, DVD or floppy disk drives, a memory card/stick orwireline and/or wireless communications, as illustrated in step S151 inFIG. 16. A received image is evaluated to determine if it contains apredetermined security image which designates the image a prohibitedimage, as illustrated in step S152. If the image does not contain apredetermined security image, NO in step S152, then the document isevaluated by detecting for the presence of one or more predeterminedattributes which are preferably uniquely associated with a prohibiteddocument as discussed above, as illustrated in step S153. If the imageis not determined to be a prohibited image to reproduce, microprocessor1404 provides instruction to printer 1414 to print the image.

When a prohibited image is detected, YES in steps S152 and S154,microprocessor 1404 preferably inhibits printer 1414 from reproducingthe document and stores illegal activity documentation informationdocumenting the attempted illegal activity into a log on memory 1412.The illegal activity documentation is preferably held in memory 1412 sothat law enforcement authorities may open up the database and review theillegal activity. The stored illegal activity documentation informationmay include an identification of the document attempted to bereproduced, such as an image of the document, identification of thesource of the image of the document (e.g. from a web server, scanner,etc.), user identification such as the computer identification and useraddress, and date and time of attempted illegal activity. The illegalactivity documentation may also include the path of the illegal documentfrom emails and the Internet, such as web addresses, and the length oftime the user spent on particular websites, the screen name and whatservers the document came from. Servers that host the websites wouldpreferably contain a similarly programmed microprocessor, such as havingthe same program or as having a specially designated guard chip. If theuser is logged on the internet, microprocessor 1404 may also initiate asilent communication with law enforcement authorities by usingcommunication software or device 1410 to connect to the authority'sserver 1421 without the user's knowledge or initiation and send theillegal activity documentation information. If the user is not loggedonto the Internet, microprocessor 1404 will preferably cause thecommunication to be sent upon the next or later logon operations.Microprocessor 1404 may also cause a computer in which it resides (notshown) to be shut down, and/or to also shut down an email system if thedocument was received from another computer when an illegal operation isdetected.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

1. A document carrying a latent image comprising: a background areaformed at a first color; a first latent image portion printed with aline frequency at a first angle and a second color; a second latentimage portion printed with a line frequency, at the first angle and athird color; the first latent image portion and the second latent imageportion overlapping within a common area that is separate from thebackground area which at least partially surrounds the common area; thecommon area of the first latent image portion and the second latentimage portion appearing as substantially the same color as the firstcolor so that the latent image is obscured to the eye; and the firstlatent image portion including printed lines, dots or spots, and thesecond latent image portion includes printed lines, dots or spots placedbetween adjacent printed lines, dots or spots of the first imageportion.
 2. The document of claim 1, wherein the first and second latentimage portions are printed with the same line frequency so that when thedocument is reproduced by a copying or scanning device, a solid tonalcolor is reproduced within the common area of the first and secondlatent image portions in substantially the same color as the firstcolor, thereby not reproducing the first and second latent imageportions as a visible image in a copy of the document.
 3. The documentof claim 1, wherein the line frequency of the second latent imageportion is lower than the line frequency of the first image portion sothat when the document is reproduced by a copying or scanning device, acomposite image of the first latent image portion and the second latentimage portion is formed as a visible image in a copy of the document. 4.The document of claim 3, wherein a copy of the document containsdistortions.
 5. The document of claim 3 in which the line frequency ofthe first latent image portion is greater than 175 lines per inch. 6.The document of claim 5 in which the line frequency of the second latentimage portion is between 50 and 135 lines per inch.
 7. The document ofclaim 1, wherein the first image portion is a holographic image.
 8. Thedocument of claim 1, wherein the first image portion is art work.
 9. Thedocument of claim 8, wherein the first latent image portion and thesecond latent image portions are formed after the creation of the artwork.
 10. The document of claim 1, wherein the first image portion is aphotograph.
 11. The document of claim 10, wherein the first latent imageportion and the second latent image portions are formed after thecreation of the photograph.
 12. A method of authenticating the documentof claim 1 as an original document comprising the steps of: reviewingthe document for the presence of predetermined security images which arenot reproduced when a reproduction of the document is made by a copyingor scanning device; and determining the document not to be an originalif the predetermined security images are not present in the document.13. The method of claim 12, further comprising the steps of comparing alayout of the document to a layout of the original document, anddetermining the document to be an original document if the layout of thedocument corresponds to the layout of an original document.
 14. Themethod of claim 13, further comprising the step of displaying a messageindicative of whether the document has been determined to be an originaldocument.